Illuminated inspection apparatus

ABSTRACT

Method of and apparatus for inspecting articles while they are being treated in a heated furnace and conveyed through a brightly illuminated area. The viewing area of the apparatus is arranged in angular relation to the light sources to afford protection for an observer from the glare of the light sources while permitting satisfactory examination of an article passing through the area.

United States Patent Inventors Robert E. Maltby, Jr.

Perrysburg; Albert W. Olson, Toledo, both of Ohio Appl. No, 872,878Filed Oct. 31, 1969 Patented Nov. 30, 1971 Assignee Libbey-Owens-FordCompany Toledo, Ohio ILLUMINATED INSPECTION APPARATUS 4 Claims, 8Drawing Figs.

US. Cl 240/2.l8, 126/200, 240/2 AD, 240/2 W Int. Cl F2ls 1/00, F 2 1 v 33/00 Field of Search 240/218, 2

AD, 2 W, 2 AT; 350/319; 126/200 [56] References Cited UNITED STATESPATENTS 1,887,654 11/1932 Mahon 126/200 UX 2,368,350 1/1945 Ellison240/218 2,733,706 2/1956 Feder 1. 126/200 2,747,568 5/1956 Dupler126/200 X 3,192,575 7/1965 Rosenau, Jr, et a1 126/200 X 3,316,468 4/1967Hanks 1. 126/200 X Primary ExaminerLouis R. Prince AssistantExaminer-Daniel M. Yasich Alt0rney-Collins & Oberlin ABSTRACT: Method ofand apparatus for inspecting articles while they are being treated in aheated furnace and conveyed through a brightly illuminated area. Theviewing area of the apparatus is arranged in angular relation to thelight sources to afford protection for an observer from the glare of thelight sources while permitting satisfactory examination of an articlepassing through the area.

PATENTED urn/30 |97| SHEET 1 BF 4 SPECIFICATION The inspection apparatusof this invention is made up of observation units in one wall of aheated furnace and similarly formed units in an opposite wall of thefurnace that are equipped with sources of light. More particularly, theinvention provides an inspection apparatus wherein units havingtransparent areas are arranged in one wall of a furnace in angularrelation to units having sources of light in an opposite wall.

An important object of the invention is to protect an observer fromobjectionable glare from the light source while affording satisfactoryand complete inspection of articles being treated within a furnace.

Another object of the invention is to provide an apparatus of the abovecharacter in which the units for the purpose of observation and forproviding a source of light are constructed to prevent loss of heat fromthe furnace.

Another object of the invention is to provide novel mounting means forthe observation units and light units in the walls of a furnace wherebyto enable installation and removal in a convenient manner. I

Other objects and advantages of the invention will become more apparentduring the course of the following description when read in connectionwith the accompanying drawings.

In the drawings, wherein like numerals are employed to designate likeparts throughout the same:

FIG. 1 is a fragmentary side elevation of a furnace provided with aninspection apparatus, constructed in accordance with the invention;

FIG. 2 is a similar view from the opposite side of the furnace;

FIG. 3 is a horizontal sectional view taken on the plane of line 3-3 ofFIGQl;

FIG. 4 is an enlarged transverse, vertical sectional view taken on theplane ofline 4-4 of FIG. 1;

FIG. 5 is a fragmentary horizontal sectional view taken on the plane ofline 5-5 of FIG. 1;

FIG. 6 is a perspective view, partly in section, of the framing membersfor glass panels;

FIG. 7 is a fragmentary enlarged transverse, vertical sectional viewtaken on the plane of line 7-7 of FIG. 3; and

FIG. 8 is a horizontal sectional view taken on the plane of line 8-8 ofFIG. 7.

DETAILED DESCRIPTION OF THE INVENTION With reference now to FIG. 1 ofthe drawings, there is shown the installed assembly of a plurality ofobservation units, generally designated by the numeral 10, that aremounted within a frame 11 located in the wall 12 ofa furnace 13. As seenin FIG. 3, the observation units are arranged in angular relation tolike units 15 similarly mounted in a frame 16 that is located in theoppositely disposed wall 17 of the furnace 13. A plurality ofhorizontally disposed, operably-driven conveyor rolls 20 are arranged,in parallelism, between the walls 12 and 17 and have shafts 21 journaledin bearings 22 supported on a framework 23 adjacent the furnace wall 17.Additionally, the units 15 are each provided with a lamp housing 25within which is contained a light source for the observing and carryingout inspection operations.

Generally speaking, the units 10 and 15 are substantially the same inconstruction and are mounted in the same manner within their respectiveframes 11 and 16. In FIGS. 4 and 5, the structure of frame 11, as hereinto be described, is duplicated in the structure of frame 16. Thus, theframe 11 is formed with upper, lower and oppositely disposed sidewalls30, 31 and 32, respectively, that are generally of a Z-shape crosssection and have an integral mounting flange 33. According to the numberof units to be mounted in the frame, such as four in FIG. 1, webs 35having the same Z-shape wall structure are located in spaced relationbetween the upper wall and lower wall 31 and integrally formed with thesidewalls 32. The frame 11 is bodily received within the walls 36 of anaperture or viewing opening 37 in the furnace wall 12. Preferably, alayer of insulation material 38, such as asbestos, is located betweenthe frame, the walls 36 and the outer surface panel 40 of the wall 12.As shown in detail in FIG. 4, and also as in FIG, 1, latch plates 45,supported on fixed threaded studs 46, are adapted to be urged by thenuts 47 against the flange 33 of the frame 11 to secure the same withinthe opening 37. This is the same at the top, bottom and sides of theframe 11 as well as of the frame 16, With regard to frame 16 as in FIG.3, it will be seen to be located within the walls 50 of an opening 51that is pro vided in the wall 17 in angular relation to the longitudinalplane thereof.

The body of each unit 10, and/or 15, is formed with upper, lower andsidewalls 55, 56 and 57, respectively, that are of a Z-shape crosssection, and a mounting flange 58. A supporting frame 60 for a pluralityof glass panes is received within the upper, lower and sidewalls of theunit. This supporting frame 60 is formed by the assembly of bars 61having grooves 62, arranged in parallel with one another, and miteredend surfaces 63 (FIG, 6). The bars are preferably of a material whichhas good heat-resistant properties to reduce conduction of heat to theglass panes and also provide a normally long anticipated length ofservice.

The glass panes, indicated at 65, 66 and 67, are received in the grooves62 as each bar is fitted around a marginal edge of the panes. When thesupporting frame 60 is located in the body of the unit 10 or 15, it issecured therein by a retaining member 68 that is fixed by screws 69against the several walls 55, 56 and 57. As indicated in the drawings,the frame is rather loosely received between particularly the top wall55 and sidewalls 57 of the unit body to avoid pinching" of the edges ofthe glass panes as the frame is being located. This is also true withregard to the edges of the panes in the grooves 62. When a unit If) isto be mounted in the frame 11, as in FIGS. 1 and 5, a layer of asbestos70 is placed against the frame and the unit is then secured by keeperplates 71 that are secured against the flange 58 by bolts 72 threadedinto the flange 33.

It has been found practical to employ glass panes having goodheat-resistant characteristics, such as glasses commercially availableunder the trademark Pyrex, for at least the inner pane 65 if not themedial pane 66 as well. On the other hand, the pane 66 and the pane 67can be of regular plate glass. And, since the frame 60 can be readilyremoved from the body of the associated unit, the panes can be cleanedor replaced while the bars 61 are removed from their marginal edges. Itis believed apparent when a unit is to be removed that a replacementunit of like size can be relatively rapidly substituted in its place toreduce heat loss from the furnace or undesired entry ofcooler air.

With reference now to FIGS. 2, 3, 7 and 8, it will be seen that eachlamp housing 25 is provided with a mounting element 74 in the form of anopen-ended box 75 having a planar wall 76 with integral top and bottomwalls 77 and sidewalls 78. The top and bottom walls 77 have ports orholes 79 for ventilation of the box 75 while the sidewalls 78, on theirouter surfaces are equipped with mounting flanges 80.

A case 82 for the light source is fixedly mounted on the outer surfaceof wall 76 and, like the mounting element 74, is realized in anopen-ended box 83 having a planar wall 84 with integral top and bottomwalls 85 and sidewalls 86 and 87. The walls 85 are provided withventilation ports 88. A closure door 90 for the case 82 is swingablymounted on the sidewall 87 by means of hinges 91 secured thereon wherebythe open end of the case can be suitably closed. The door 90 is held bya latch arrangement including an eyebolt 92, swingably mounted by abracket 93 on the sidewall 86, a keeper plate 94 on the door 90 and awingnut 95.

The case 82 is secured by its wall 84 to the wall 76 of the box 75 bymeans of threaded studs 96, fixed in the wall 76, passing throughaligned openings in the wall 84 and with nuts 97 thereby securing thismounted relation. The walls 76 and 84 are provided with registeringopenings to afford a passageway 98 through which the rays from the lightsource 100 will be projected.

For the purposes of this invention, an electric lamp is employed that isadapted to function satisfactorily in relatively high ambienttemperatures. For this reason, the light source 100 is an iodine quartzlamp, such as can be obtained commercially by the listing "SylvaniaSOO/Q/CL Single-Ended Iodine Quartz Lamp. This lamp is received in asocket [01 supported by means of a bracket 102 on the wall 84.

The unit 15 with the lamp housing 25 is mounted and secured in the frame16 by means of the flanges 80 on the sidewalls 78 of the mountingelement 74. As the unit is being located within the frame, a layer ofinsulation material 106, such as asbestos, is placed between the flange58 and the frame. Clamping plates 107 on bolts 108, threaded into theflanges of the frame 16, are placed against the flanges or brackets 80to firmly maintain the unit in position as the bolts are turned into theflanges 33.

MODE OF OPERATION With particular reference to FIG. 3, it will be notedthat the provision of several panes of glass in a supporting frame ofheat-resistant material provides a relatively large area for theobservation of articles being treated within a heated furnace withoutloss of heat or entry of cooler air. Such protection from transmissionof heat through the units 10, through which the articles can be seen,reduces any discomfort to a person making an inspection. This samemanner of protection also serves to substantially lower any damagingeffect on the sources of light in the housings 25 on the units 15. Theaxial plane T of the opening 37 in the wall 12 of the furnace is locatedin substantially transverse relation to the longitudinal axial plane Lof the furnace. On the other hand, the axial plane A of the opening 51in the wall 17 is arranged in predetermined angle to the axial plane Lsuch that the beams of light from the lamps 100 will be more or lessfully directed toward the inner surface of the wall 12 and not directlytoward the opening 37. These beams of light in consequence "provide awide, highly illuminated field through which an article, designated bythe numeral 110, will be conveyed.

This manner of illumination has been employed to good advantage in theinspection of transparent articles 110, such as sheets or plates ofglass and articles produced therefrom. Usually a sheet of glass issupported in a vertical plane on a rack or similar form of carrier 111by which it is conveyed on the rolls 20 through the furnace. Suchinspection is made by an observer whose line of vision is preferablyalong a plane indicated by the letter V. When so located, the observerwill have substantially complete opportunity to inspect the transunits15 is such that the vision of an observer will not be impaired by thebrilliance of the light beams while he is viewing an article along aplane, such as the plane V, which is an angle of convenience to both theplane T of the opening 37 and the plane A of the opening 51.

It is also realized the manner of installing the units 10 and 15 intotheir respective frames 11 and 16 provides for rapid securement as wellas for easy removal for cleaning and/or replacement of the glass paneswhen the bars 61 of the supporting frame are separated therefrom.

We claim:

1. In apparatus for visually inspecting transparent articles beingconveyed along a predetermined path within an enclosed chamber havingoppositely disposed sidewalls, the improvement comprising a firstopening in one of said sidewalls, a tubular extension projectingoutwardly from said opening in a direction inclined to said path, aglazing frame at the outer end of said tubular extension, a transparentglazing sheet in said glazing frame, means directing light through saidtransparent sheet and along sard tubular extension to illuminate saidarticles, a second opening in the other of said sidewalls, a glazingframe in said'second opening, and a transparent glaz ing sheet in saidlast-named glazing frame permitting observation of illuminated portionsof said transparent articles along a sight line at an angle to andintersecting both said path of movement and said light path.

2. Apparatus for visually inspecting articles being conveyed along apredetermined path as claimed in claim I, in which each of said glazingframes includes a plurality of said transparent glazing sheets in spacedface-to-face relation, and said light-directing means includes a lightsource within-a case carried by said tubular extension outwardly of saidtransparent glazing sheets.

3. Apparatus for visually inspecting articles being conveyed along apredetermined path as claimed in claim l, including a plurality of saidfirst openings, tubular extensions, glazing frames and light-directingmeans in superimposed relation in said one wall, and a plurality ofcorresponding second openings and glazing frames in superimposedrelation in said other wall permitting observation over a large area ofsaid articles moving along said path.

4. Apparatus as defined in claim 1, in which said glazing frames aregenerally Z-shaped in cross section, and each of said frames is glazedwith a plurality of sheets of glass to close said wall openings andinsulate said light source and said observation point from the interiorof said chamber while permitting the passage of light.

1. In apparatus for visually inspecting transparent articles beingconveyed along a predetermined path within an enclosed chamber havingoppositely disposed sidewalls, the improvement comprising a firstopening in one of said sidewalls, a tubular extension projectingoutwardly from said opening in a direction inclined to said path, aglazing frame at the outer end of said tubular extension, a transparentglazing sheet in said glazing frame, means directing light through saidtransparent sheet and along said tubular extension to illuminate saidarticles, a second opening in the other of said sidewalls, a glazingframe in said second opening, and a transparent glazing sheet in saidlast-named glazing frame permitting observation of illuminated portionsof said transparent articles along a sight line at an angle to andintersecting both said path of movement and said light path. 2.Apparatus for visually inspecting articles being conveyed along apredetermined path as claimed in claim 1, in which each of said glazingframes includes a plurality of said transparent glazing sheets in spacedface-to-face relation, and said light-directing means includes a lightsource within a case carried by said tubular extension outwardly of saidtransparent glazing sheets.
 3. Apparatus for visually inspectingarticles being conveyed along a predetermined path as claimed in claiml, including a plurality of said first openings, tubular extensions,glazing frames and light-directing means in superimposed relation insaid one wall, and a plurality of corresponding second openings andglazing frames in superimposed relation in said other wall permittingobservation over a large area of said articles moving along said path.4. Apparatus as defined in claim 1, in which said glazing frames aregenerally Z-shaped in cross section, and each of said frames is glazedwith a plurality of sheets of glass to close said wall openings andinsulate said light source and said observation point from the interiorof said chamber while permitting the passage of light.